Photographic products, compositions and processes utilizing 3-cyano-4-azo-5-pyrazolone dye developers



United States Patent 3,309,199 PHOTOGRAPHIC PRODUCTS, COMPOSITIONS AND PROCESSES UTILIZING 3-CYANO-4- AZO-S-PYRAZOLONE DYE DEVELOPERS Daniel L. Ross, Cambridge, Mass, assignor to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware No Drawing. Filed Dec. 31, 1962, Ser. No. 248,240 29 Claims. (Cl. 96-29) This invention relates to photography and more particularly to products, compositions and processes for the development of photosensitive silver halide elements.

It is one object of the present invention to provide novel processes and compositions for the development of silver halide emulsions, in which novel colored silver halide developing agents are used.

Another object is to provide novel processes and compositions for the development of silver halide emulsions, in which the novel silver halide developing agent is capable of developing an exposed silver halide emulsion and imparting a reversed or positive colored image of the developed image to a superposed image-receiving material.

Further objects are to provide said novel silver halide developing agents, and novel products, processes and compositions suitable for use in preparing monochromatic and multichromatic photographic images by the employment of said novel silver halide developing agents.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the processes involving the several steps and the relation and order of one or more of such steps with respect to each of the others, and the products and compositions possessing the features, properties and the relation of elements which are exemplified in the following detailed disclosure, and the scope of the application of which will be indicated in the claims.

The objects of this invention may be accomplished by the use of certain novel dyes which have the ability to develop an exposed silver halide emulsion; thus these dyes may be referred to as dye developers. These novel dyes or dye developers will be further described hereinafter.

The dye developers and the photographic processes and compositions disclosed herein are particularly useful in the treatment of an exposed silver halide emulsion, whereby a positive dye image may be imparted to another element, herein referred to as an image-carrying or imagereceiving element.

US. Patent No. 2,983,606, issued May 9, 1961 to Howard G. Rogers, discloses diffusion transfer processes wherein a photographic negative material, such as a photographic element comprising an exposed silver halideemulsion, is developed in the presence of a dye developer -to impart to an image-receiving layer a reversed or positive dye image of the developed image by permeating into said emulsion a suitable liquid processing composition and bringing said emulsion into superposed relationship with an appropriate image-receiving layer. The inventive concepts herein set forth provide novel dye developers which may be advantageously used in such processes.

In carrying out the process of this invention, a photosensitive element containing a silver halide emulsion is exposed and wetted with a liquid processing composition, for example by immersing, coating, spraying, flowing, etc., in the dark, and the photosensitive element superposed prior to, during or after wetting, on an image-receiving element. In a preferred embodiment, the photosensitive element contains a layer of dye developer, and the liquid processing composition is applied to the photosensitive element in a uniform layer as the photosensitive element is brought into superposed position with an image-receiving element. The liquid processing composition permeates the emulsion to provide a solution of dye developer substantially uniformly distributed therein. As the exposed silver halide emulsion is developed, the oxidation product of the dye developer is immobilized or precipitated in the developed areas, thereby providing an imagewise distribution of unoxidized dye developer dissolved in the liquid processing composition. This immobilization is apparently due, at least in part, to a change in the solubility characteristics of the dye developer upon oxidation, and especially as regards its solubility in alkaline solutions. It may also be due, in part, to a tanning effect on the emulsion by the oxidized developing agent. At least part of this imagewise distribution of unoxidized dye developer is transferred, by imbibition, to a superposed image-receiving layer. The image-receiving layer receives a depthwise diffusion, from the emulsion, of unoxidized dye developer, without appreciably disturbing the imagewise distribution thereof, to provide a reversed or positive, colored image of the developed or negative image. The image-receiving element may contain agents adapted to mordant or otherwise fix the diffused, unoxidized dye developer. Imbibition periods of approximately one minute have been found to give good results, but this contact period may be adjusted where necessary to compensate for variations in temperature or other conditions. The desired positive image is revealed by separating the imagereceiving layer from the silver halide emulsion at the end of the imbibition period.

The dye developers of this invention may be utilized in the photosensitive element, for example in, on or behind the silver halide emulsion, or they may be utilized in the image-receiving element or in the liquid processing composition. In a preferred embodiment, a coating or layer of the dye developer is placed behind the silver halide emulsion, i.e., on the side of the emulsion adapted to be located most distant from the photographed subject when the emulsion is exposed and preferably also adapted to be most distant from the image-receiving layer when in superposed relationship therewith. Placing the dye developer behind the emulsion layer, as in the preferred embodiment, has the advantage of providing increased contrast in the positive image, and also minimizes any light-filtering action by the colored dye developer. In this preferred embodiment, the layer of dye developer may be applied by using a coating solution containing, e.g., about 0.5 to 8%, by weight, of the dye developer. Similar concentrations may be used if the dye developer is utilized as a component of the liquid processing composition. In an especially useful mode of disposing the dye developers in the phototsensitive elements, the dye developer is dissolved in a water-immiscible solvent and then dispersed in a gelatin coating solution.

The liquid processing composition which is used in the processes herein disclosed comprises at least an aqueous solution of an alkaline compound, for example, diethylamine, sodium hydroxide or sodium carbonate, and may contain the dye developer. In some instances, it may contain an additional silver halide developing agent. If the liquid processing composition is to be applied to the emulsion by being spread thereon, preferably in a relatively thin, uniform layer, it may also include a viscosity-increasing compound constituting film-forrning material of the type which, when spread over a water-absorbent base, will form a relatively firm and relatively stable film. A preferred film-forming material is a high molecular weight polymer such as a polymeric, water-soluble ether inert to an alkali solution, as, for example, a hydroxyethyl cellulose or sodium carboxymethyl cellulose. Other film-forming materials or thickening agents whose ability to increase viscosity is substantially unaffected when left in solution for a long period of time may also be used.

The novel azo dye developers of this invention may be represented by the formula:

wherein R is an alkylene group, preferably a lower alkylene group containing no more than five carbons and more preferably an ethylene (-CH CH or trimethylene (CH CH CH group; Ar is an aryl radical, such as benzene or naphthalene; Ar is a phenyl radical, including substituted phenyl radicals; each Z is an alkyl group, preferably a lower alkyl group, such as methyl or ethyl, an alkoxy group, preferably a lower alkoxy group, such as methoxy, or a halogen, such as chlorine; n is 0, 1 or 2; m is or 1; and Y is a para-dihydroxyphenyl or an ortho-dihydroxyphenyl group which also may be nuclear substituted by alkyl or halogen groups.

In a preferred embodiment, the aryl radicals Ar and Ar are benzene radicals, and such dye developers may be represented by the formulae:

wherein Y, R, Z, m, and n have the same meaning as above, and X is hydrogen, alkyl, hydroxyalkyl, halogen, haloalkyl, and alkoxy radicals, wherein the alkyl and alkoxy components of said radicals are preferably lower alkyl and lower alkoxy. Where desired, more than one X substituent may be present, e.g., as in 2,4,6-trichlorophenyl. In general, X may be any of the substituents generally present in l-phenyl-S-pyrazolone azo couplers.

The novel dye developers of this invention may be prepared by diazotizing a compound of the formulae:

wherein Ar, R, Z, n and Y have the same meaning as above, and particularly a derivative wherein the hydyroxyl groups of Y are protected, e.g., an O-acylated derivative, and coupling the diazotized compound into the desired coupling component. Ar preferably is a benzene radical.

The preparation of amino compounds within the Formula C is disclosed in U.S. Patent No. 3,019,107, issued to Elkan R. Blout, Milton Green, Howard G. Rogers, Myron S. Simon and Robert B. Woodward, on January 30, 1962, and in a continuation-in-part thereof, Ser. No. 98,287, filed Mar. 27, 1961, now U.S. Patent No. 3,236,- 893 issued February 22, 1966. The preparation of protected derivatives of these amino compounds, such as the 4 bis-acetoxy derivatives, is disclosed and claimed in U.S. Patent No. 3,019,254, issued to Milton Green and Helen P. Husek, on January 30, 1962.

As examples of compounds within Formula C, mention may be made of:

p-aminophenethyl-hydroquinone 2-(4-aminonaphthylethy1)-hydroquinone 2-(p-an1inophenethyl) -5-methyl-hydroquinone Z-(p-aminophenethyl) -5-chloro-hydroquinone 2-(3'-methyl-4-arninophenethyl)-hydroquinone 2- (p-aminophenethyl -5 ,6-dimethyl-hydroquinone 2- p-aminophenethyl -3,5 ,6-trimethyl-hydroquinone 2-rn-aminophenethyl-hydroquinone p-aminophenylmethyl-hydroquinone Z-(m-aminophenethyl)-5-methyl-hydroquinone 1,2-dihydroxy-4-(p-aminophenethyl)-benzene 2-['y-(4-aminophenyl) -fl-methyl-propyl] -hydroquinone 2- ['y-(4'-aminophenyl -propyl] -hydroquinone 2- (4-amino-3'-rnethoxy-phenethyl) -hydroquinone 2- ['y- (3 -amino-4'-methylphenyl -propyl] -hydroquinone 2-(p-amin0phenethyl) -6-methyl-hydroquinone Z-(p-aminophenethyl)-5-bromo-hydroquinone 2-(5-aminonaphthylethyl)-hydroquinone Particularly useful dye developers are those prepared from p-aminophenethyl-hydroquinone and 2 ['y (4'- aminophenyl) -propyl] -hydroquinone.

As noted above, R preferably is a lower alkylene group. It will be understood that the selection of particular alkylene, alkyl and alkoxy groups in the compounds of Formulae C and D may be varied as desired, so long as the resulting dye developer is capable of being dissolved in the alkaline photographic processing solution and of transferring by difiusion within a reasonable imbibition time.

The preparation of amino compounds within Formula D and O-acylated derivatives thereof is disclosed in the copending applications of Myron S. Simon, Serial Nos. 196,463 (now U.S. Patent No. 3,134,811 issued May 26, 1964) and 196,464 [now abandoned), both filed May 21, 1962.

As examples of compounds within Formula D, mention may be made of:

2-(p-aminophenyl)-5-methyl-hydroquinone Z-(p-aminophenyl) -5-chloro-hydroquinone 2-( 3 -methyl-4-aminophenyl -hydroquinone 2- (p-aminophenyl)-5,6-dimethyl-hydroquinone 2-(4-aminonaphthyl)-hydroquinone Z-(m-aminophenyl)-5-methyl-hydroquinone 2-(4'-amino-3methoXy-phenyl) -hydroquinone 2- p-aminophenyl -6-methyl-hydroquinone 2-(p-aminophenyl) -S-bromo-hydroquinone 2-(4'-amino-2',5 '-dirnethoxy-phenyl)-hydroquinone 2- 4-amino-2-chloro-phenyl -hydroquinone 2- 4'-amino-2-methyl-phenyl -hydroquinone 2- (o-aminophenyl)-hydroquinone The selection of solubilizing groups as substituents of the azo coupler radical, including their exclusion or inclusion, provides a useful means of modifying the solubility and diifusion properties of the resulting dye developer to meet the requirement of any particular application.

The azo coupling is generally performed at a pH which is preferably not greater than about 9. The hydroxy groups of Y are protected during diazotization and coupling, as by the formation of bis-acetoxy derivative; such bis-acetoxy derivatives are described in the aforementioned U.S. Patent 3,019,254 and copending application Serial No. 196,464 (now abandoned).

The azo coupling component of these novel dye de velopers are 1-aryl-3-cyano-5-pyrazolones. The use of these cyano-pyrazolones gives dye developers of good color properties for use in subtractive multicolor transfer processes, and exhibiting unexpected increased light stability. The preferred cyano-pyrazolones of this invention correspond to the formula:

n-CN HO in which X is as defined above. As examples of particularly suitable l-aryl-3-cyano-5-pyrazolones, mention may be made of:

I [ON HO If 1-p-tolyl-3-cyano-5-pyrazolone lHgCH l-(p-ethyl) -phenyl-3-cyano-5-pyrazolone 1-phenyl-3-cyano-5-pyrazolone I or.

1-m-trifluoromethyl-phenyl-3-cyano-5-pyrazolone .ol l

l CHZOHZOH sitory intermediates in the preparation of 3-carboxy-5- pyrazolones by hydrolysis of the cyano group.

The synthesis of suitable 1-aryl-3-cyano-5-pyrazolones is described in the following nonlimiting examples:

Example 1 .I-p-tolyl-3-cyano-5-pyrazol0ne To a solution of 7.46 g. @0375 mole) of diethyl cyanosuccinate in 175 ml. of pyridine was added the diazonium solution prepared by diazotizing 2.69 g. (0.025 mole) of p-toluidine in 50 ml. of water and 5 cc. of concentrated hydrochloric acid with 1.75 g. of sodium nitrite at 05 C. This solution was stirred at 20 C. for 20 minutes, following which 50 ml. of triethylamine and ml. of 2% aqueous sodium hydroxide were added. After 1.5 hours of stirring, the solution was poured into 400 ml. of concentrated hydrochloric acid and 1 kg. of ice. The resulting creamy solid was collected and washed with water. It was dissolved in ml. of 2% sodium hydroxide, and the solution was washed with three 50 ml. portions of ether. The washed solution was acidified with 5% hydrochloric acid, and the product was collected and crystallized from acetic acid. Following collection of the crystallized product and washing with benzene, 3.15 g. (64%) of 1-p-tolyl-3-cyano-5-pyrazolone was obtained, melting at 209l0 C. with decomposition.

Analysis.-Calculated: C, 66.32%; H, 4.55%; N, 21.10%. Found: C, 65.41%; H, 4.52%; N, 20.98%.

Example 2 l-(p-ethyl)-phenyl-3-cyano-5-pyraz0lone was prepared in a manner similar to that set forth in Example 1 using pethyl aniline and diethyl cyanosuccinate. The precipitated product was recrystallized from benzene to give 58% of light tan crystals, melting at 172-3 C. with decomposition.

Example 3 1 (p-hydroxyethyl)-pheny1-3-cyano-5-pyrazolone was 1-p-tolyl-3 -cyano-4- p-'(2",5 "-d-ihydroxyphenethyl phenylazo] -5-pyrazolone (XIV) 1(p-ethyl)-phenyl-3-cyano-4-[p-(2",5"-dihydroxyphenyl) -phenylazo] -5-pyrazolone (XV) l-(p-hydroxyethyl)-phenyl-3cyano-4-[p-(2",5"-

dihydroxyphenyl)-phenylazo] -5-pyrazolone (XVI) l-(p-ethyl)-phenyl-3-cyano-4-[m-(2",5"-dihydroxyphenethyl) -phenylazo] -5-pyrazolone (XVII) 1- (p-hydroxyethyl -phenyl-3 -cyano-4- [m- 2",5

dihydroxyphenethyl) -phenylazo] -5-pyrazolone The preparation of dye developers within the scope of this invention is described in the following nonlimiting examples:

Example 4 1 (p hydroxyethyl) phenyl-3-cyano-4-[rn-(2,5"- dihydroxyphenyl)-phenylazo]-5-pyrazolone was prepared as follows: To a solution of 2.29 g. (0.01 mole) of l-(phydroxyethyl)-phenyl-3-cyano-5-pyrazolone, prepared as in Example 3, in 60 ml. of water, 60 ml. of ethanol and 20 ml. of saturated sodium bicarbonate solution was added the diazonium solution prepared by adding, at 5 C., sodium nitrite (0.7 g.) to a solution of 3.21 g. (0.01 mole) of m-(2,5'-diacetoxyphenyl)-aniline hydrochloride in 50 ml. of water, 50 ml. of acetone, and 2.5 ml. of concentrated hydrochloric acid. There was an immediate precipitation of an orange dye. After 2.5 hours of stirring, the mixture was acidified with 10% acetic acid solution and 300 ml. of water was added. The resulting precipitate was collected and washed with water. The dye was suspended in 300 ml. of methyl Cellosolve and nitrogen was bubbled through with stirring for 30 min. A solution of 8 ml. of 50% sodium hydroxide solution in 88 ml. of water, which had been deaerated with a stream of nitrogen, was then added and the solution was stirred at room temperature for 45 min. The dye developer was precipitated by the dropwise addition of a deaerated solution of 100 ml. of acetic acid in 1000 ml. of water, collected and purified by dissolving in 150 ml. of methyl Cellosolve containing ml. of acetic acid, filtering, and adding dropwise with stirring 600 ml. of water. The product was collected and dried in vacuum over potassium hydroxide to give 3.60 g. (81.5%) of yellow dye, melting at 188- 189.5 C., with decomposition. A solution of this material in butyl Cellosolve exhibits a Amax. of 415 1111.0.

Example 5 1 p tolyl 3 cyano-4-[p-(2",5" dihydroxyphenethyl)-phenylazo]-5-pyrazolone was prepared from p-(2,5- diacetoxyphenethyl)-aniline and 1-p-tolyl-3-cyano-5-pyrazolone by the procedure described in Example 4. The re-precipitated product melted at 208-209 C., with decomposition. A solution of this material in butyl Cellosolve exhibits a Amax. of 432 m Example 6 1 p tolyl 3 cyano-4-[m-(2",5"-dihydroxyphenyl)- phenylazo1-5-pyrazolone was prepared from m-(2,5-diacetoxyphenyl)-aniline and 1-p-tolyl-3-cyano-5-pyrazolone by the procedure described in Example 4. The product as isolated from hydrolysis reaction was recrystallized from toluene and melted at 225226 C. with decomposition. A solution of this material in butyl Cellosolve exhibits a kmax. of 416 m Example 7 1 (p ethyl) phenyl 3 cyano-4-[m-(2",5"-dihydroxyphenyl)-phenylazo]-5-pyrazolone was prepared from m (25' diacetoxyphenyl) aniline and 1-(p-ethyl)- phenyl-3-cyano-5-pyrazolone by the procedure described in Example 4. The product as isolated from the hydrolysis reaction was recrystallized from toluene, and melted at 206207 C. with decomposition. A solution of this material in butyl Cellosolve exhibits a Amax. of 412 m Example 8 1 p tolyl 3 cyano-4-[m-(2,5"-dihydroxybenzyl)- phenylazo]-5-pyrazolone was prepared from m-(2',5-diacetoxybenzyl)-aniline and 1-p-tolyl-3-cyano-5-pyrazolone in a manner similar to that set forth in Example 4. The product as isolated from the hydrolysis reaction was recrystallized from toluene, and melted at 2067 C. with decomposition. A solution of this material in butyl Cellosolve exhibits a Amax. of 424 mp.

Other dye developers within the scope of this invention may be prepared by the procedures described in the above examples by substituting the desired intermediates within Formulae C and D and the desired 1-aryl-3-cyano-5-pyrazolone.

The following examples of the use of the novel dye developers of this invention in diffusion transfer processes are given for purposes of illustration only.

Example 9 A photosensitive element was prepared by coating a subcoated cellulose acetate film base with a layer of gelatin containing a dispersion of 1-p-tolyl-3-cyano-4-[p-2", 5 dihydroxyphenethyl) phenylazo]-5-pyrazolone dissolved in a mixture of cyclohexanone and n-butylacetanilide. A blue-sensitive iodobromide emulsion was coated over the layer of dye developer. The resulting photosensitive element then was exposed. An aqueous processand an image-receiving element as said elements were brought into superposed relationship. The image-receiving element was prepared by coating a 2:1 mixture by weight of polyvinyl alcohol and polya4-vinyl pyridine and a small amount of 1-phenyl-5-mercaptotetrazole, as disclosed in the copending application of Howard C. Haas, Ser. No. 50,848, filed Aug. 22, 1960 (now US. Patent No. 3,148,061 issued September 8, 1964). After an imbi'bition period of approximately 1 minute, the imagereceiving element was separated and contained a positive yellow dye image, D max. 2.03, D min. 0.30. The stability to light of dye images made in this manner was tested by an accelerated fading test in which the transfer dye image was swa-bbed with 2% aqueous boric acid immediately after imbibition and then exposed to a xenon are (over saturated NaCl for 20 hours. As a control, a transfer image of substantially the same density obtained by the use of 1-phenyl-3-N-n-hexy1carbamyl-4-[2, 5"-dihydroxyphenethyl)-phenylazo] -5-pyrazolone on the same image-receiving layer was simultaneously exposed to the xenon are. After 2 0 hours exposure to the xenon arc, the dye image obtained from 1-p-tolyl-3-cyano-4-[p-Z, 5 "-dihydroxyphenethyl) -phenylazo] -5-pyrazol0ne showed markedly less fading than did the control image.

Example 10 The procedure described in Example 9 was repeated with each of the dye developers of Examples 4, 6 7 and 8. The resulting transfer dye images each also exhibited unexpectedly less fading than the control dye image when subjected to the xenon are accelerated fading test described in Example 9.

The dye developers of this invention are also useful in integral multilayer photosensitive. elements for use in multicolor diffusion transfer processes. As an example of such photosensitive elements, mention may be made of the photosensitive elements disclosed and claimed in the copending US. application of Edwin H. Land and Howard G. Rogers, Ser. No. 565,135, filed Feb. 13, 1956', wherein at least two selectively sensitized photosensitive strata are superposed on a single support and are processed, simultaneously and without separation, with a single common image-receiving element. A suitable arrangement of this type comprises a support carrying a red-sensitive silver halide emulsion stratum, a green-sensitive silver halide emulsion stratum and a blue-sensitive silver halide emulsion stratum, said emulsions having associated therewith, respectively, a cyan dye developer, a magenta dye developer and a yellow dye developer. In one of the preferred embodiments of photosensitive elements of this type, the dye developers are disposed in separate alkali-permeable layers behind the photosensitive silver halide emulsion stratum with which they are associated.

The photosensitive elements within the scope of this invention may be used in roll film units which contain a plurality of photosensitive frames. The photosensitive elements of this invention are especially useful in composite roll film intended for use in a Polaroid Land Camera, sold by Polaroid Corporation, Cambridge 39, Mass, or a similar camera structure such, for example, as the camera forming the subject matter of U.S. Patent No. 2,435,717, issued to Edwin H. Land on Feb. 10, 1948. In general, such composite roll films comprise a photosensitive roll, a roll of image-receiving material and a plurality of pods containing an aqueous alkaline processing solution. The rolls and pods are so associated with each other that, upon processing, the photosensitive element may be superposed on the image-receiving element and the pods may be ruptured to spread the aqueous alkaline processing solution between the superposed elements. The nature and construction of the pods used in such units are well known to the art. See, for example, US. Patents Nos. 2,543,181 and 2,634,886, issued to Edwin H. Land.

It will be noted that the liquid processing composition may contain one or more auxiliary or accelerating silver halide developing agents, such as p-methylaminophenol (Metol); 2,4-diaminophenol (Amidol); benzy-laminophenyl; hydroquinone; a substituted hydroquinone such as toluhydroquinone, phenylhydroquinone, or 4-methylphenylhydroquinone; or a 3-pyrazolidone such as 1- phenyl-3-pyrazolidone. These silver halide developing agents are substantially colorless, at least in their unoxidized form. It is possible that some of the dye developer oxidized in exposed areas may be oxidized by an energy transfer reaction with oxidized auxiliary developing agent.

In addition, development may be affected in the presence of an onium compound, particularly a quaternary ammonium compound, in accordance with the processes disclosed and claimed in the copending application of Milton Green and Howard G. Rogers, Ser. No. 50,851, filed Aug. 22, 1960 (now U.S. Patent No. 3,173,786 issued March 16, 1965).

The dye developers of this invention may be used also in conventional photographic processes, such as tray or tank development of conventional photosensitive films, plates or papers to obtain black and white, monochromatic or toned prints or negatives. By way of example, a developer composition suitable for such use may comprise an aqueous solution of approximately 12% of the dye developer, 1% sodium hydroxide, 2% sodium sulfite and 0.05% potassium bromide. After development is completed, any unreacted dye developer is washed out of the photosensitive element, preferably with an alkaline washing medium or other medium in which the unreacted dye developer is soluble. The expression toned is used to designate photographic images wherein the silver is retained with the precipitated dye, whereas monochromatic is intended to designate dye images free of silver.

It should be noted that the dye developers of this medium are self-sufiicient to provide the desired color image and do not depend upon coupling reactions to produce the desired color. They thus provide a complete departure from conventional photographic color processes in which the color is produced by a coupling reaction between a color former or coupler and the oxidized developing agent, as well as so-called auto-coupling processes in which color is obtained by a reaction of the oxidized developing agent with unoxidized developing agent.

It will be apparent that, by appropriate selection of the image-receiving element from among suitable known opaque and transparent materials, it is possible to obtain either a colored positive reflection print or a colored positive transparency. Likewise, the inventive concepts herein set forth are adaptable for multicolor work by the use of special photographic materials, for example, film materials of the type containing two or more photosensitized elements associated with an appropriate number of imagereceiving elements and adapted to be treated with one or more liquid processing compositions, appropriate dye developers suitable to impart the desired subtractive col ors being incorporated in the photosensitized elements or in the liquid processing compositions. Examples of such photographic materials are disclosed in U.S. Patent No. 2,647,049 to Edwin H. Land.

As examples of useful image-receiving materials, mention may be made of nylon, e.g., N-methoxymethyl-polyexamethylene adipamide, polyvinyl alcohol, and gelatin, particularly polyvinyl alcohol or gelatin containing a dye mordant such as poly-4-vinylpyridine. The image-receiving element also may contain a development rcstrainer, e.g., 1-p-henyl-5-mercaptotetrazole, as disclosed in the copending application of Howard G. Rogers and Harriet W. Lutes, Serial No. 50,849, filed August 22, 1960 (now U.S. Patent No. 3,265,498 issued August 9, 1966).

The dye developers herein set forth are also useful in the formulation of colored images in accordance with the photographic products and processes described and claimed in US. Patent No. 2,968,554, issued to Edwin H. Land on January 17, 1961.

The novel compounds herein disclosed are also suitable for use as dyes for textile fibres, such as nylon.

In the preceding portions of the specification the expression color has been frequently used. This expression is intended to include the use of a plurality of colors to obtain black.

Since certain changes may be made in the above products, compositions and processes without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. A hotographic developer composition comprising an aqueous solvent, an alkaline material soluble therein, a silver halide developing agent which is substantially colorless in at least the unoxidized form, and an azo dye developer of the formula:

wherein Y is selected from the group consisting of p-dihydroxyphenyl, o-dihydroxyphenyl radicals and alkyl and halogen nuclear substituted p-dihydroxyphenyl and odihydroxyphenyl radicals; Ar is an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei, said N=N- group being directly attached to a ring carbon of said aryl nucleus Ar; R is a divalent alkylene group directly attached to said aryl nucleus Ar and to said phenyl ring of Y; each Z is selected from the group consisting of halogen, alkoxy and alkyl radicals; n is from O to 2, inclusive; m' is from 0 to 1, inclusive; and Ar is a phenyl radical.

2. A photographic developer composition as defined in claim 1, wherein Ar and Ar are benzene radicals, R is ethylene, m is 1 and n is 0.

3. A photographic developer composition as defined in 13 claim 1, wherein Ar and Ar are benzene radicals, n is and m is 0.

4. A photographic developer composition comprising an aqueous alkaline solution of l-p-tolyl-3-cyano-4-[p- (2",5" dihydroxyphenethyl) phenylazo1-5-pyrazolone and a silver halide developing agent which is substantially colorless in at least the unoxidized form.

5. A photographic developer composition comprising an aqueous alkaline solution of 1-(p-ethy=l)-phenyl-3- cyano 4-[-m-(2",5"-dihydroxyphenyl)-phenylazo]-5-pyrazolone and a silver halide developing agent which is substantially colorless-in at least the unoxidized form.

6. A photographic developer composition comprising an aqueous alkaline solution of l-(p-hydroxyethyD-phenyl 3-cyano-4- [m-(2",5"-dihydroxyphenyl) -phenylazo] pyrazolone and a silver halide developing agent which is substantially colorless in at least the unoxidized form.

7. A photographic developer composition comprising an aqueous alkaline solution of 1-p-tolyl-3-cyano-4-[m- (2",5"-dihydroxyphenyl)-phenylazo]-5-pyrazolone and a silver halide developing agent which is substantially colorless in at least the unoxidized form.

8. A photographic developer composition comprising an aqueous alkaline solution of 1-p-t0lyl-3-cyano-4-[m-(2", 5"-dihydroxybenzyl)-phenylazo]-5-pyrazolone and a silver halide developing agent which is substantially colorless in at least the unoxided form.

9. A photographic product comprising a support, a silver halide emulsion in a layer carried "by said support and an azo dye developer in a layer carried by said support on the same side thereof as said silver halide emulsion, said azo dye developer being a compound of the formula:

wherein Y is selected from the group consisting of p-dihydroxyphenyl, o-dihydroxyphenyl radicals and alkyl and halogen nuclear substituted p-dihydroxyphenyl and o-dihydroxyphenyl radicals; Ar is an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei, said N=N group being directly attached to a ring carbon of said aryl nucleus, A-r; R is a divalent alkylene group directly attached to said aryl nucleus Ar and to said phenyl ring of Y; each Z is selected from the group consisting of halogen, alkoxy and alkyl radicals; n is from 0 to 2, inclusive; m is from 0 to 1, inclusive, and Ar is a phenyl radical.

10. A photographic product as defined in claim 9, wherein Ar and Ar are benzene radicals, R is ethylene, nisOandmis l.

11. A photographic product as defined in claim 9, wherein Ar and Ar are benzene radicals, n is 0 and m is 0.

12. A photographic product as defined in claim 9 wherein said azo dye developer is 1-p-tolyl-3-cyano-4-[p-(2", 5"-dihydroxyphenethyl)-phenylazo]-5-pyrazolone.

13. A photographic product as defined in claim 9 wherein said azo dye developer is l-p-tolyl-3-cyano-4-[m-(2", 5"-dihydroxybenzyl)-phenylazo]-5-pyrazolone.

14. A photographic product as defined in claim 9 wherein said azo dye developer is l-(p-ethyl)-3-cyano-4-[m-(2", 5"-dihydroxyphenyl)-phenylazo]-5-pyrazolone.

15. A photographic product as defined in claim 9 wherein said azo dye developer is l-(p-hydroxyethyl)-phenyl-3- cyano 4-[rn-(2",5-dihydroxyphenyl)-phenylazo]-5-pyrazolone.

16. A photographic product as defined in claim 9 wherein said azo dye developer is 1-p-tolyl-3-cyano-4-[m-(2 ',S- dihydroxyphenyl -phenylazo] -5-pyrazolone.

17. A photographic product as defined in claim 9, wherein said azo dye developer is in a layer positioned between said support and said layer containing said silver halide emulsion.

18. In a process of forming a phtographic image in color, the steps which comprise developing an exposed silver halide emulsion with an aqueous alkaline solution containing an azo dye developer of the formula:

wherein Y is selected from the group consisting of p-dihydroxyphenyl, o-dihydroxyphenyl radicals and alkyl and halogen nuclear substituted p-dihydroxyphenyl and o-dihydroxyphenyl radicals; Ar is an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei, said N=N- group being directly attached to a ring carbon of said aryl nucleus, Ar; R is a divalent alkylene group directly attached to said aryl nucleus Ar and to said phenyl ring of Y; each Z is selected from the group consisting of halogen, alkoxy and alkyl radicals; n is from 0 to 2, inclusive; m is from 0 to 1, inclusive; and Ar is a phenyl radical, to provide in said emulsion an imagewise distribution of unoxidized dye developer in undeveloped areas of said emulsion, and transferring at least part of said imagewise distribution of unoxidized dye developer by imbibition from said emulsion to an image-receiving layer in superposed relationship with said emulsion to impart a transfer image in color to said image-receiving layer.

19. The process as defined in claim 18 wherein said dye developer is disposed prior to exposure in a photosensitive element containing said emulsion and the solution containing said dye developer is formed by permeating said photosensitive element with an aqueousalkaline liquid capable of solubilizing said dye developer.

20. The process as defined in claim 18, wherein said liquid is introduced by being spread in a substantially uniform layer between said photosensitive element and an image-receiving element including said image-receiving layer as said elements are brought into superposed relationship.

21. The process as defined in claim 18, wherein said liquid contains a thickener for increasing viscosity and for facilitating the spreading thereof between said photosensitive element and said image-receiving element.

22. The process as defined in claim 18, wherein said dye developer is dissolved in an aqueous alkaline solution prior to application thereof to said exposed emulsion.

23. The process as defined in claim 18, wherein Ar is a benzene radical, R is ethylene, n is 0 and m is 1.

24. The process as defined in claim 18, wherein said dye developer is 1-p-tolyl-3-cyano-4-[p-(2",5"-dihydroxyphenethyl) -phenylazo -5-pyrazolone.

25. The process as defined in claim 18, wherein said dye developer is 1-p-tolyl-3-cyano-4-[m-(2,5"-dihydroxybenzyl aphenylazo] -5-pyrazolone.

26. The process as defined in claim 18, wherein said dye developer is l-(p-ethyl)-phenyl-3-cyano-4-[m-(2",5"- dihyd-roxyphenyl) -phenylazo] -5-pyrazolone.

27. The process as defined in claim 18, wherein said dye developer is l- (p-hydroxyethyl) -phenyl-3-cyano-4- [m- (2",5"-dihydroxyphenyl)-phenylazo]-5-pyrazolone.

28. The process as defined in claim 18, wherein said dye developer is 1-p-tolyl-3-cyano-4-[m-(2",5"dihydroxyphenyl)-phenylazo]-5-pyrazolone.

29. The process which comprises developing an exposed photosensitive silver halide emulsion with an aqueous alkaline solution of an azo dye developer of the Ar wherein Y is selected from the group consisting of p-dihydroxyphenyl, o-dihydroxyphenyl radicals and alkyl and halogen nuclear substituted p-dihydroxyphenyl and o-dihydroxyphenyl radicals; Ar is an aryl nucleus selected from the group consisting of benzene and naphthalene nuclei, said -N=N- group being directly attached to a ring carbon of said aryl nucleus, Ar; R is a divalent alkylene group directly attached to said aryl nucleus Ar and to said phenyl ring of Y; each Z is selected from the group consisting of halogen, alkoxy and alkyl radicals; n is from 0 to 2, inclusive; m is from 0 to 1, inclusive; and Ar is a phenyl radical.

References Cited by the Examiner UNITED STATES PATENTS 5/1964 Blout et al 96-29 5/1965 Simon 96-29 

18. IN A PROCESS OF FORMING A PHOTOGRAPHIC IMAGE IN COLOR, THE STEPS WHICH COMPRISE DEVELOPING AN EXPOSED SILVER HALIDE EMULSION WITH AN AQUEOUS ALKALINE SOLUTION CONTAINING AN AZO DYE DEVELOPER OF THE FORMULA: 